How much should the mod be allowed to think for the players?

[BNL]

Sometimes, the game has evolved to a point where a breaking strategy can occur to find the last remaining Mafia, or conversely the Mafia can endgame the Town. However, these games cannot be called off simply due to the *possibility* that someone is lying about their role, even though it won't happen.

This brings the question, how much is the moderator allowed to think for the players? I've had a game declared before because scum apparently devised an unbreakable plan, even though there were doubts. In very complex games, it's probably best to leave the thinking to the players themselves as it does take some work to derive those strategies.

On the other hand, I've seen n Mafia:n+1 Town going into Night always declared over by the moderator when there are known to be no protectives/vigs etc. You could argue that the Mafia can choose to play dumb and refuse to kill the next Night, but that is stretching by a lot.

So where is a good place to draw the line where the mod thinks for the players in declaring endgame and where to let the players think for themselves?